Means for magnetically maintaining metal tape in a loop in banding apparatus



Feb. 13, 1962 Filed Sept. 24, 1958 H. LUTHI MEANS FOR MAGNETICALLY MAINTAINING METAL TAPE IN A LOOP IN BANDING APPARATUS 2 Sheets-Sheet 1 INVENTOR. fl/ws [0771/ Feb. 13, 1962 H. LUTHI 3,02

MEANS FOR MAGNETICALLY MAINTAINING METAL TAPE IN A LOOP IN BANDING APPARATUS Filed Sept. 24, 1958 2 Sheets-Sheet 2 INVENTOR. ANS 10ml W/IWMH United States Patent MEANS FOR MAGNETICALLY MAINTAINING METAL TAPE IN A LOOP IN BANDING APPARATUS Hans Liithi, Zurich, Switzerland, assignor to Erapa Etablissement fuer Rationelle Verpackung und Spedition, Vaduz, Liechtenstein Filed Sept. 24, 1958, Ser. No. 762,985 Claims priority, application Germany Mar. 21, 1955 1 Claim. (Cl. 100-26) This invention relates to apparatus for binding packages, irrespective of shape, such as bales, packing cases, parcels, etc, with binding material such as a tape or wire.

The instant application is a continuation-in-part of my application, Serial Number 572,689, filed March 20, 1956 and now abandoned.

More particularly, this invention is directed to the mechanism for guiding the binding material, for example a fiat steel tape, about the package to be bound and at all times maintaining the tape in the guide means until such time as the tape is pulled taut about the package and sealed in such position.

Machines for baling packages in which a continuous, flexible binding material, for example steel tape, is guided from a supply reel in a guide means in a loop about a package to be bound, are prior known. After the package, positioned on a table or platform from which the guide means extends, is encircled by the tape, the leading end of the tape in the guide means is held by a clamping mechanism, and the loop of tape is pulled tight about the package positioned therewithin. The end regions of the tight tape loop are then fastened or welded to each other, and substantially simultaneously or immediately thereafter, the trailing end of the tape loop is cut from the supply. In such prior kno'wn package baling machines, the flexible binding material moves freely in the guide means as the material is pushed forward therein to encircle a package, and hence to prevent the binding material from falling out of the guide means, the diameter of the loop guide means, that is, the size of the packages that canbe baled, may be varied only within narrow limits. Obviously in such machines it is the guage of the flexible binding material which controls the maximum possible loop guide means diameter for the particular material of the tape or wire; and when such maximum is exceeded, its inherent rigidity will not of itself be sufiicient to retain the binding material in the guide means, particularly at the top region of the loop. In one machine of this general type and using a wire as the hinder, the package encircling loop guide means is provided with a groove having a plurality of fingered spring strips partially closing the groove at all points, the spring strips confining the baling wire within the groove when the wire is projected therethrough but allowing it to be stripped therefrom when the leading end of the wire is held against return movement and the direction of the wire feed rollers is reversed when pulling the wire taut about the package. In such machine there is a constant tendency of the wire to leave the groove on any variation in the uniform feed of the wire, when the wire meets an obstruction, or on the occurrence of a kink in the wire; and as a result thereof, the high friction between wire and groove, and the time consumed in rethreading and straightening the wire, the packaging frequency thereof is very low. In another prior known package baling machine type, the binding wire or tape is seized by a ring which is thereupon rotated about the package to be baled positioned within the ring, placing the binding about the package. In such machine, the binding tape or wire is fed by means of rollers mounted on the ring. In machines of this type there is likewise a limitation on the size of the packages which may be baled, and, in addition, this type is heavy and costly, and most important, is limited in its packaging frequency to a low figure because of the high inertia of the moving parts.

It is thus an object of the invention to eliminate to as great an extent as practicable the limitations as to the size of the packages which can be baled and banded by machine while at the same time providing a package baling machine with a highly increased packaging frequency.

It is another object of the invention magnetically to maintain the steel tape or *wire within the guide means irrespective of the dimensions of the loop formed about a package while permitting the tape or wire to advance unhindered in the guide means.

. terial as it leaves the guide means when being drawn taut and tight on the package.

My instant invention will readily be understood from the following description of an illustrative embodiment thereof when read in conjunction with the appended drawing in which:

FIGURE 1 is a high-1y simplified, partially perspective, elevational diagram of a complete package baling machine of the type having a stationary loop guide for the baling tape; and

FIGURES 2 and 2a are a front, partially broken away, view of a region of the guide including one tape maintaining element, and a side sectional view thereof, respectively.

Referring to FIGURE 1, the package banding apparatus employing a metal tape of steel, for example, comprises a plurality of feed rollers I, a tape tensioning mechanism II, a tape feeding mechanism III, a reverse stop mechanism IV, a tape gripping device V, a tape cutting means VI, a tape welding structure VII, a clamping device VIII, a ring or loop tape guide IX, a driving gear assembly X, and control equipment. The complete apparatus of FIGURE 1 is disclosed and described in detail in my copending application for patent, Serial Number 566,987, filed February 21, 1956, in which the broad aspects thereof are claimed. The instant application is directed to the features of the ring or loop tape guide IX.

Loop guide IX, to which the metal banding tape 10 is supplied by rollers I, by way of assemblies II to VIII, comprises a ring-shaped guide channel 11, which is positioned substantially vertical on the platform or table 12 of the banding apparatus. The surface of table 12 is provided with a plurality of longitudinal rollers 13 for advancing the package to be banded into the aperture defined by the loop guide, the latter being open at an edge region of platform 12 and vertically positioned so as to be aligned with a space between two adjacent platform rollers 13, or between the most forwardly roller 13 and the front of the table as shown in FIGURE 1. The banding tape 10 is fed into such space by the tape feed mechanism III, while the tape gripping device V, the clamping device VIII, the welded structure VII, and the tape cutting means VI, all are positioned at the longitudinal mid-region of such space. The open end of the ring guide channel .11 spans the longitudinal dimension of such space, and the banding tape 10 is fed into 3 the left hand portion of the loop guide channel 11 at the leftwardly open end, as shown in FIGURE 1, to travel clockwise in the channel.

At spaced intervals, which may be regular or irregular in their distances apart, a plurality of magnets 14 are inserted or incorporated in the channel surface 15 along which the tape slides, the channel having an invented-U cross-section of which the side walls 16 are of sufiicient length to assist in longitudinally keeping the tape Within the channel. Magnets 14, which preferably are saturated permanent magnets, comprise cylinders 14a within bushings 17 threaded, or otherwise afiixed, in channel 11. I have found that a ratio of the diameter of the cylindrical magnets 14a to their length of at least 1 to 2 /2, or even better, of 4 to 11, is preferable in most instances; that is, with a smaller ratio the attractive power of the magnets is not quite sufiicient. In FIGURE 1, I have shown a plurality of eight magnets spaced along the channel 11, but it is apparent that the number, size and positioning of the magnets depends on the weight of the steel band 11, the crosssection thereof, as also on the diameter of the loop and the feeding speed of the band. Each magnet 14a is press fitted into its bushing 17, which extends somewhat beyond the external end surface of the magnet remote from the channel to prevent displacement of the magnet in the event that the external end of the magnet assembly is accidentally subjected to a force directed inwardly toward the channel. The inner face 18 of each magnet is ground to the tape sliding surface 15 of the channel so that the tape 10 will not strike thereagainst but will readily slide thereover. For purposes of clarity, this feature is somewhat exaggerated in FIGURES 2 and 2a. By way of example, for a tape of 0.5 mm. thickness, the diameters of the magnets 14a is 6.0 to 8.0 mm. and the speed of the tape feed is about 2 to 3 meters per second.

What I claim is:

In a package banding machine, a guide means for a metal banding material in the form of a loop about the package, the guide means being unobstructed inwardly toward the package and having an outer wall on the inner surface of which the metal banding material is adapted to slide, the outer wall being formed with a References Cited in the tile of this patent UNITED STATES PATENTS 1,650,843 McChesney Nov. 29, 1927 2,604,831 Fraenckel July 29, 1952 2,831,422 Black et a1. Apr. 22, 1958 2,853,938 Hall et al. Sept. 30, 1958 

